This is an application to renew the NICHD P-30 Population Center grant to Princeton University's Office of Population Research (OPR) for a five-year period beginning July 1, 1999. The objective of the NICHD-supported Population Research Center is to provide a cohesive and efficient interdisciplinary structure in which high-quality research can be conducted at Princeton University. The Center achieves this goal by (1) supplying centralized computing, administrative, and library facilities and services; (2) providing venues for researchers from diverse backgrounds to communicate and collaborate about current research and future plans; (3) organizing regular and specialized seminars about research underway both on and off campus; and (4) mobilizing support for demographic research at the University. The Center consists of an Administrative Core, a Data Analysis (Computing and Statistical Services) Core, and a Library Core, which provide support services to individual investigators conducting demographic research that has been determined eligible for support of core services. This application requests support for each of these cores. The Center's research associates have been highly successful attracting extramural funding, and since the last application, research funding has grown by a factor of 2.5. For Year 1 of the funding period we have six active federal grants, an additional six approved for funding (with very high priority scores), one pending re-submission, and eight non-federal active grants approved for access to NICHD core services. There are currently 31 professional researchers associated with OPR who are working on projects in several major areas of demographic research, including aging, child wellbeing, family and household demography, fertility and fecundity, statistical and demographic methods, health and mortality, employment and human capital, migration and urbanization, and population and environment.